Add base data migration

[theferrit32]

This task is to create a migration file in cloud storage that only contains base data. This enables loading a genegraph instance with the base data without needing to redownload and load those files into Jena.

For kubernetes deployments using this migration as GENEGRAPH_DATA_VERSION environment variable, in order to reload the stream data upon redeployment of a new code version, the commit or image hash needs to be included in the /data/ directory path so they do not collide. Right now they don't collide (at least in staging) because those cloudbuilds update the GENEGRAPH_DATA_VERSION variable in the architecture repo to include the image hash, under the assumption that all deployments will create a migration file with the image hash in the filename, in a helm hook prior to being deployed.